#ifndef SOUND_AUTOMATICALLYCHOSENSOUNDSYSTEM_H_
#define SOUND_AUTOMATICALLYCHOSENSOUNDSYSTEM_H_

#include "base/common.h"
#include "base/logging.h"
#include "base/scoped_ptr.h"
#include "sound/soundsysteminterface.h"
#include "sound/soundsystemproxy.h"

namespace cricket {

	// A function type that creates an instance of a sound system implementation.
	typedef SoundSystemInterface *(*SoundSystemCreator)();

	// An AutomaticallyChosenSoundSystem is a sound system proxy that defers to
	// an instance of the first sound system implementation in a list that
	// successfully initializes.
	template <const SoundSystemCreator kSoundSystemCreators[], int kNumSoundSystems>
	class AutomaticallyChosenSoundSystem : public SoundSystemProxy {
	public:
		// Chooses and initializes the underlying sound system.
		virtual bool Init();
		// Terminates the underlying sound system implementation, but caches it for
		// future re-use.
		virtual void Terminate();

		virtual const char *GetName() const;

	private:
		base::scoped_ptr<SoundSystemInterface> sound_systems_[kNumSoundSystems];
	};

	template <const SoundSystemCreator kSoundSystemCreators[], int kNumSoundSystems>
	bool AutomaticallyChosenSoundSystem<kSoundSystemCreators,
		kNumSoundSystems>::Init() {
			if (wrapped_) {
				return true;
			}
			for (int i = 0; i < kNumSoundSystems; ++i) {
				if (!sound_systems_[i].get()) {
					sound_systems_[i].reset((*kSoundSystemCreators[i])());
				}
				if (sound_systems_[i]->Init()) {
					// This is the first sound system in the list to successfully
					// initialize, so we're done.
					wrapped_ = sound_systems_[i].get();
					break;
				}
				// Else it failed to initialize, so try the remaining ones.
			}
			if (!wrapped_) {
				LOG(LS_ERROR) << "Failed to find a usable sound system";
				return false;
			}
			LOG(LS_INFO) << "Selected " << wrapped_->GetName() << " sound system";
			return true;
	}

	template <const SoundSystemCreator kSoundSystemCreators[], int kNumSoundSystems>
	void AutomaticallyChosenSoundSystem<kSoundSystemCreators,
		kNumSoundSystems>::Terminate() {
			if (!wrapped_) {
				return;
			}
			wrapped_->Terminate();
			wrapped_ = NULL;
			// We do not free the scoped_ptrs because we may be re-init'ed soon.
	}

	template <const SoundSystemCreator kSoundSystemCreators[], int kNumSoundSystems>
	const char *AutomaticallyChosenSoundSystem<kSoundSystemCreators,
		kNumSoundSystems>::GetName() const {
			return wrapped_ ? wrapped_->GetName() : "automatic";
	}

}  // namespace cricket

#endif  // SOUND_AUTOMATICALLYCHOSENSOUNDSYSTEM_H_
